Basic components for detached garage system

I'm a newbie to the forum and to solar, and would like your advice and input. I'm planning a small system to do two things:

1. Power a small CF light (~25w) in a chicken coop for up to 5 hours/day on a timer during the winter months.
2. Run a 1/2 hp garage door opener a couple times a day.

If there were power left to power a few outlets (maybe to run a small shopvac occasionally) that would be nice, too. It would cost me under $1000 to run power from the house (need to run a line under a road), so I'm trying to keep the budget for solar near this. These are the basic major components I thought would fit my needs:

Questions: Is this panel any good? I've seen one post by one member here in favor of this company, but that's all I've seen. Seems that for $300 shipped, I can't go wrong if it works at all, but I don't know for sure.
Also: if I want to use more power in the garage, can the Sunlight charger handle two 125w panels? I realize that's over 20A by a little bit.
Lastly: I intend to put components (other than the panel) in the garage, which is unheated but very well insulated (better than our house, in fact). The water bottle I keep in the car only freezes when it gets below 0F outside. I know cold is hard on batteries, and the inverter specifies use only above 32F. Am I asking for trouble by having all this in an unheated location?

Would anyone here do anything differently for a small, economical system? Any advice is appreciated!

The GP-1000 appears to MSW, inexpensive, but not good for many inductive loads. May have a high idle current, I dunno, but would bet that it would not start a 1/2 HP motor. Bet that the shop vac may demand a bit too much current, as well.

You might want a 12 V CFL, or even LED light for the chickens.

How about a wind-up spring motor for the door opener, with a battery remote control ... get a lilttle exercise, and save a lotta hardware etc ... OH, that is not what you asked.

Vic, I checked and I think you are right about the surge capacity not up to the needs of the motor. One main reason I picked the GP-1000 is that it has (what seems to me to be) a low standby draw -- 0.2A. Is there a better choice of inverter (that is, low standby draw, over 2000w surge, and still not very expensive)? Otherwise I suppose I could get a DC door opener, right?

We already have fun with manually lifting the door, but I thought it would be a nice use for a little part of the chicken-lighting system (we want to keep the hens laying through more of the winter).

Mike90045, I did a little snooping around and found that my location (near Madison, WI) gets about 4 peak sun hours per day through the winter months (which is when I'll be using the system most).

I was going to get a 12vDC CFL, since that is what the charger puts out at the lighting output, and I didn't think it was worth it to get a dedicated inverter just for that one light. The lumen output of LEDs is likely insufficient for my needs -- most LEDs have no more lumens per watt than CFL's, from what I know about them. Both emit somewhere between 50-75 lpw. I need a bare minimum of 500 useable lumens, so figuring about half the light stays in the coop, that's about the output of a 25w CFL after it runs in and gets a bunch of dust on it.

I know nothing of this inverter, I guessed that it might have a largeish standby current. It is lower than I had guessed, and has quite a bit lower idle current than mine!

I have not followed the lower cost inverter market, so I should not comment farther on that.

Yes, I had thought about a DC motor for the door. There are some safety issues with powered garage doors, so you would need to be a bit careful in adapting a DC motor to the existing door, or rolling your own.

Good luck with your project. Others here will have a lotta good info. Vic

The next largest Go Power inverter is 1500w, but the standby loss is something like 1.2A. Can any two matched inverters be doubled up (is this 'stacking'?) to provide twice the amperage of each inverter alone?

I'm having trouble understanding just what inverter can be used on such a little (one-panel) system -- seems standby loads of 1 amp wastes a significant percentage of the overall output of the system. (One amp = 12 watts) x 24 hours = 288 watthours. Can that be right? That is over half of the total power of the system I'm contemplating.

I'd check with a local Morningstar dealer, or call the factory directly, and ask if there is a chance the SS 300 could start the motor. Garage door motors may not have the big surge induction motors have, and it may work, with very low stand-by power, and pure sine wave.

Unsually, invepensive inverters are not designed for any kind of stacking, either series or parallel -- again, I have not followed the market. Often these manufacturers are far too busy taking out parts to lower the cost, to have any time left to think of what features they might add.

Yes, I think your standby power calc is correct. This, of course, makes your wonderment about a DC Door operator a very good one. There might just be something floating around on the net as a 12 VDC retrofit for a door operator. I have not looked, as I have no functional garage, let alone an operator for the door.

Mike, if the motor for the door is really 1/2 HP, then it prob would need about 700-800 Watts to run it after it starts. ALtho if these motors are rated similar to shop vacs, then this could be a "Peak HP" kinna deal. I dunno, and that is all I know.

On watt ratings: I have a central wood furnace with 2 blowers, and each blower is rated by the manufacturer as drawing 2.8 amps continuous and 6.3 amps startup. The kill-a-watt meter says the two of them together draw 275w (2.3 amps) continuous. But, the power factor is .52, so is the real power consumption about twice the wattage shown on the meter? That would make sense of the manufacturer's ratings. But I don't know how to measure the peak watts.

I could put the watt meter on the garage door opener and learn something, I'll bet.

Personally, I would give up on the door opener idea. Why waste the time and money required to do what you can do simply by hand? Even a large door can be opened easily if it is designed correctly. If it is a large door, a chain hoist type drive might be in order.

Icarus, I feel like I understand the basic thought behind nixing the garage door opener: the best way to save electricity is to simply quit using so much of it. We had power to the garage when we bought the house, but it was on its own meter which the power company (sorry, "Co-op") charged us $300 a year for the privilege of looking at whether we used any power or not. So we had it disconnected. Now, we have this 'chicken light' excuse to experiment with solar power, and if we can run a few items in the garage too, then we can better justify the whole system. Or so the reasoning goes. We heat about 95% with wood that I cut, hand shovel a 60' driveway, mow the lawn with a manual reel mower, raise or hunt over half our meat...I'm OK with swallowing my pride on the garage door

SteveK, that's the sort of unit I was thinking about in my earlier post, but I didn't have a clue whether it could be adapted to be fed with 12vdc directly. Would you suggest to just remove the battery from the opener and feed it directly from the PV storage batteries? I'm assuming I can't split the 12vdc feed from the charge controller to supply power both to the PV storage batteries and the opener battery (or can I do this?).

I tested the power consumption on the opener we have. The label on the opener says it needs 6A, but the Kill-a-watt says it draws 360w when running (no light bulb installed), and 6w when idle (this is less than ideal). I don't think I have a way to test the start-up surge, though, but I would guess it would be less than 3X the running wattage. So, it seems that the 1000w inverter I was thinking about might run it.

I would keep the battery in the GDO and charge it from your main bank if desired. The GDO does not operate on a cycle counter. It will run until the batt voltage goes too low and the unit swtches off. The batteries they use are SLA therefore I would suspect a very cost effective charger would suffice (even a simple on/off charger). There are more knowledgeable folk here to help you with that, I'm a "millwright" and do only garage doors and operators.

Keep in mind that the radio portion of the GDO's logic board will still be active in limp mode and you will still have some draw when it's sitting idle. Edited: I'll find out on Monday just how much if the distributor has some open boxes

Have you considered allowing the inverter to power the GDO only to re-charge the GDO batts when the chicken coop lights are on 5 hours a night then switching off the inverter? This could double as the light switch for the coop. Most people only open their garage doors 3 times a day max....that's not much of a load on that battery after all.

Switching off the inverter will do two thing for you. It will allow you to get a little larger inverter and not worry so much about the no-load current drain. I like the Victron Phoenix 350W. It will supply 700W surge, 91% efficient and can be switched. That would not solve the motors on the stove. I use a coal stoker and it also has two motors, feeder and combustion and uses upto 55W. I use the above inverter to run it and a chest freezer no problems...

Oh, and if you have no other way into the garage make sure you add a key release in case the operator breaks. It allows you to pull on the release rope from outside the door..

I would keep the battery in the GDO and charge it from your main bank if desired. The GDO does not operate on a cycle counter. It will run until the batt voltage goes too low and the unit swtches off. The batteries they use are SLA therefore I would suspect a very cost effective charger would suffice (even a simple on/off charger). There are more knowledgeable folk here to help you with that, I'm a "millwright" and do only garage doors and operators.

SteveK, thanks for all this info. I hope you or someone can tell me, please: can I run two chargers (the Morningstar Sunlight and this 'very cost effective charger') off the same panel? I researched a bit and learned that I can't use one and the same charge controller to charge the two different battery banks. If I can simply hook up an additional small charge controller to the main 12v source, this sounds like it will work!

I spoke with Morningstar about this very issue last week. I was considering using a Power Supply (effectively a battery in this case) as the front end to a charge controller to construct a makeshift battery charger. They said no problem, we do it all the time in our test lab, just place a 1/4 Ohm power resistor in between the charge controller and the supply (aka battery).

So I'd think you are good to go from what I know...

The low cost chargers (really defined as regulators) are not UL approved if that makes a difference to you.

SteveK, I understand what you're saying, I think, but I'm not sharp enough to catch what I'm supposed to do. Are you saying that if I put a 1/4 w power resistor in between the main PV storage battery bank and the Morningstar controller, then I could use a separate charger connected directly to that same battery bank to charge the GDO battery?

I spoke with Morningstar about this very issue last week. I was considering using a Power Supply (effectively a battery in this case) as the front end to a charge controller to construct a makeshift battery charger. They said no problem, we do it all the time in our test lab, just place a 1/4W power resistor in between the charge controller and the supply (aka battery).

So I'd think you are good to go from what I know...

The low cost chargers (really defined as regulators) are not UL approved if that makes a difference to you.

Well, you'd connect the input of the charger/regulator to the main battery bank. The battery bank that your PV's charge through your main charge controller.

So you would feed the charger for the GDO from the main battery bank that is the storage for your entire system. In between the main battery and the secondary charger/regulator you would fit a 1/4 Ohm power resistor in series with one of the feed lines. Morningstar did not specify +or- on the feed lines.

Properly fused of course....

I have a Rube Goldberg mentality sometimes but I don't believe I am a mile off here. If I am I hope someone else that has much more expertise around here (like most anyone) will please chime in and correct me.

It would be good to feed the GDO directly form the main batts but I just don't know the maximum input voltage the GDO's logic board could survive so the onboard battery is my best solution.

OK, sounds simple. What does the resistor do? I mean, why would we need to reduce the current flowing from the Morningstar (the main charge controller) to the battery in this setup? I don't know much about this, but I thought the amount of current that the charge controller sends to the battery was carefully controlled by the charge controller to make sure the battery charges fully without overcharging, etc.

It would be good to feed the GDO directly form the main batts but I just don't know the maximum input voltage the GDO's logic board could survive so the onboard battery is my best solution.

Y'know, I was thinking of this too, but worried about the size of cable necessary to send that much 12v power from the battery to the GDO. Seems a charger wouldn't send more than an amp or so to the GDO battery, which would require a very modest cable.

OK, sounds simple. What does the resistor do? I mean, why would we need to reduce the current flowing from the Morningstar (the main charge controller) to the battery in this setup? I don't know much about this, but I thought the amount of current that the charge controller sends to the battery was carefully controlled by the charge controller to make sure the battery charges fully without overcharging, etc.

I didn't ask him to elaborate on it but he said you'd want something between it. I believe it is more for if something goes wrong with the controller fed from the batts.

At any rate I'd use the resistor. Why? Hopefully others can elaborate.

Check the specs, but you probably should have a 20-25 amp maximum fuse between the controller and the high voltage battery bank (probably 1/2 that for a 24 volt or 1/4 that for a 48 volt system). Put the fuse in the positive lead to the PV input on the controller (assuming the rest of your system is negative ground).

My guess on the 1/4 ohm resistor is just to limit surge current when being first connected (charging internal capacitors). It may also limit some other momentary maximum current input in the design too--but I don't know the design (solar panels cannot surge current--so they do not need a fuse to protect the downstream charge controllers).

The 1/4 ohm fuse can give 2-3 volt (maximum) drop--A waste of energy, but not an issue if connecting to a 24 or 48 volt battery bank.

I don't think this scheme will work well. A 12V battery can't really fully charge another 12V battery. Siphoning off power to an additional charge controller, and it's internal losses will never work. the 2nd battery will always be low, and therefor begin to did quickly.

I think that this works with a 24 v battery, 1/4 resistor, and 2nd controller to a 2nd 12V battery, then you have enough voltage to fully charge the 2nd battery.

The resistor is needed because the PWM charge controllers do NOT have a current limit, only a fuse. They directly connect the solar array to the battery in quick pulses. Without the resistor, this would burn out things quickly. I think a 1ohm resistor may be a better value personally, at least to start with. for a 10A controller, for wattage you should start with 20 watt size of resistor.

1) Connect two charge controllers to the panel -- one to charge the main battery bank, and one to charge the battery of the GDO.

2) Get an inverter large enough to run the AC GDO I already have. The Xantrex X-Power 1500w should be large enough, I think; it has a 3000w surge rating. It also has low standby consumption (0.3A). Are these X-Power inverters any good? I'm guessing they are at least as good as the Go Power brand. Am I being penny wise and pound foolish by considering low-end inverters at all?

I should add to look at the standby losses, low power efficiency, and how you will turn it on and off.

If this is a12 volt system, I really like the small 300 watt morning star tsw inverter and if you need more power at times, a second larger less expensive inverter you manually turn on and off.

But plan out your system first before buying anything, this whole design phase is a balancing act of battery bank, array, inverter against your loads/needs.

-Bill

Thank you for this advice. I am trying to keep an eye on standby losses since this system will not produce too many AH to start with. My loads/needs is a difficult part of all this, since I have it in my head to run the garage door opener -- too large of a load, even though infrequently. This is the reason that the 300w Morningstar won't work for me -- the GDO needs almost 400w to run, and much more (which I have no way to calculate accurately) to start. And, unfortunately, I can't plan to turn off the inverter, since then the garage door remote won't register (pretty much defeating the idea of having an electric GDO if I have to go turn on the inverter first). Relatedly, I ruled out inverters that have a 'sleep' feature that isn't user-adjustable, since the sleep threshold on non-adjustable inverters is right around the standby draw of the GDO (~6w), so it would be impossible to predict whether the inverter would sleep or not.